I connect to internet via Mobile Broadband which is actually a USB 3G Modem. How do I use that to send SMS. For windows they have provided a software.
I used a very convoluted manner to make things work.
First up, install sakis3g and use it to convert your USB device into a modem. Connecting to internet using sakis3g is straightforward.
Now, sakis3g does one good thing. It switches your modem if it is not switched. So, use it to switch your modem and you'll have new entries in /dev/ starting with ttyUSB (like ttyUSB0, ttyUSB1, ttyUSB2, ttyUSB3) All those correspond to the various capabilities of your modem. In my E1550 USB0 worked with wammu.
Run guided configuration for connecting phone.
Connection type --> USB
Phone type --> None of the above
Connection type --> AT based
USB Port --> /dev/ttyUSB0 (worked for me, try the others if it doesn't)
If wammu recognized it in the next step, you're up!
Connect to the phone, create a message, enjoy!
* is the number that works